Thread: Abrasive Grit Comparison Sheet

Originally Posted by sebell

I suppose the back of my GlassStones counts as
`in-writing'...

1000 mesh - 14.7 micron
2000 mesh - 7.35 micron
4000 mesh - 3.68 micron
8000 mesh - 1.84 micron
16000 mesh - 0.92 micron
30000 mesh - 0.49 micron

- Scott

Pam on Knifeforums just posted something interesting...

For the glass stone series,

Divide 14,700 by the grit size and you have the particle size in microns.

Divide 14,700 by the micron and you get the grit.

Multiply the grit by micron and you get 14,700.

(some of the numbers give small errors due to rounding. For example, the 4000 grit stone should have a 3.675 micron size, but since shapton only takes things to the hundredths, they round up to 3.68.)

So, apparently shapton considers a stone that has a one micron abrasive size to be a 14,700 grit stone.

Glenn - I completely understand your skepticism, I felt the same way at first, but after working on this for quite a while and trying comparisons of things like US to European sand paper and Norton to Japanese stones, I am forced to believe it....

BUT, don't take my word for it...compare what your glass stone says or better yet, their web site
(Ceramic On Tempered Glass : Shapton® Stones, Shapton® Sharpening Systems)

to what Norton says about their stones on their site

(http://www.nortonstones.com/Media/Do...nesCatalog.pdf)


Here's the kicker, and it gets me every time....I know that the scratch pattern from my Norton 4000 grit water stone (6 micron) is bigger than the scratch pattern from a friend's 4000 grit King water stone (3 micron), because I was able to see a sizable difference with a microscope...

...BUT...

....What these manufacturers don't say anything about, which could potentially make a HUGE difference (and does), is what the particles are made of and what shape they are.....

....I have seen some of the members on here saying that they would rather use 1 micron CrOx than 0.25 micron diamond paste because supposedly the diamond paste is so much more harsh, and as far as that goes, I saw a thread from ChrisL that said he got a reasonably comfortable shave from what was supposedly 50 micron CrOx, so what the actual sharpening media is made of DOES make a difference, since even ChrisL mentioned that he wouldn't try this with 500 grit sand paper....

Please let us know what you think of your Shapton Glass 4K shave compared to your Norton 8K shave....

...my guess is that the Norton will be smoother....Why, has to do with "Why Shaptons?"......the answer as far as I have ever heard is because Shaptons are more aggressive and work much faster.....but this might have the side effect of giving you a rougher shave also.

You might also try shaving from the Shapton Glass 8K and the Norton 8K and see if you think there is a significant difference in the feel of the two shaves....

I'm not at all an experienced honer, but I will say that I think this information has explained some things about problems I've had with honing. In my recent honing, I've been treating my King 4k and my Naniwa 8K like the Norton 4K/8K combo that is recommended around here--in pyramids and the like. I was getting good edges, but not great, and under magnification they looked very rough, like the 1k scratches were still present, even after a couple of rounds of aggressive pyramids.

HOWEVER, after reading this thread and reexamining my hones, I started doing pyramids with my 2K super stone and 4K King, then polishing on the 8K, and I am getting MUCH better edges, and they are glassy smooth under magnification. Of course, my use of pressure and the like is probably getting better just from more practice, but I can't help but think that the 2K/4K is a much better combination for smoothing out the low level scratches from my 1K diamond plate (which is actually not that great, and tears razors up something awful, but is really really fast for honing out chips and the like).

This would also tie in to my experience with the Japanese "Lapika" brand lapping film I picked up--clearly marked 2K=9 micron, 4K=3 micron, 8K=.5 and 10K =.3.

Glen and Smokintbird,

You both have valid arguments IMO. While the particle sizes are known, what isn't covered in the list (and can't be) is the "polish effect" of the stones. As it was said, the Norton 8K feels "smoother" than the 8K SG.

SG's add more scratches to get a smooth consistency while Nortons (and kings, pastes and nagura stones) "rub" the surface smooth with "softer" scratches.

I've been calling this the new school (Shapton) and the old school (Naniwas Norton, King, etc....) concepts. The new school uses a series of stones that quickly progresses by adding scratches, while the old school potentially uses less stones, but spends more time on each one in order to smooth out the surfaces.

As for me, I'm definitately in the new school camp.

Originally Posted by Smokintbird

Absolutely perfect!

I intend to post it on a couple other forums as well.....I have seen lots of partial comparisons, but I have never seen any references to back them up, and I just don't trust everything I read.

Hi, it appears that Olivia took the jis tables from one of my pages... I can't give you a reference for the data to proove its accuracy, but I spent about a year with a kanji dictionary and yahoo.co.jp searching before I found a Japanese industrial abrasives manufacturer that had a detailed JIS chart showing both the old and new JIS down to this level of detail in a gif image that copied into text format:
http://members.cox.net/yuzuha/jisgrits.html
(I did not list the old JIS standards to that detail since the sedimentation tube method is obsolete but I did list a partial comparison of the old and new JIS on my Shapton grit page http://members.cox.net/yuzuha/jisgrit1.html The yellow numbers on here are purely theoretical and I calculated them for comparing Shapton's grading system to other stones and micron graded powders etc. )

Alas, I can no longer point you to the original site where I found the JIS information because the PC I had all that on died several years ago.... I also no longer have the complete details of the old JIS standard (you can download the standards from the JIS organization in English or Japanese but they charge a considerable fee to do so).

One really interesting thing to note on the detailed table though is the maximum size. 8000 grit can have a few percent 6 micron particles, which can put some dandy scratches in mean 1.2 micron finish. Also the 3% tails are interesting... The 3% below .6 microns is not very important but again it allows 3% to be between 3.5 and 6 microns and still be listed as 8000 grit!

BTW, I discovered that some of you also hang out on knife forums but some of you may not.... you can still find some useful stuff in the useful links sub forum of the kitchen knife forum over there... http://www.knifeforums.com/forums/showtopic.php?tid/759892/
http://www.knifeforums.com/forums/showtopic.php?tid/759541/
for example.

Lots of sources for stones anyway Might find some razor discussion in the "kitchen" and "keeping sharp" forums too.

Originally Posted by jendeindustries

Glen and Smokintbird,

You both have valid arguments IMO. While the particle sizes are known, what isn't covered in the list (and can't be) is the "polish effect" of the stones. As it was said, the Norton 8K feels "smoother" than the 8K SG.

SG's add more scratches to get a smooth consistency while Nortons (and kings, pastes and nagura stones) "rub" the surface smooth with "softer" scratches.

I've been calling this the new school (Shapton) and the old school (Naniwas Norton, King, etc....) concepts. The new school uses a series of stones that quickly progresses by adding scratches, while the old school potentially uses less stones, but spends more time on each one in order to smooth out the surfaces.

As for me, I'm definitately in the new school camp.

I'll second that! micron size alone will only get you in a rough ball park. For example; a surgical arkansas stone is made of daitoms which range from about 5 to 10 microns but they are bonded so tightly and closely that they produce a much finer finish than their grain size. Belgian coticule stones are rated about 8k to 10k but are full of garnets, which have a dodecahedral (20 sided) or 24 sided crystal shape. That means the edge angles are going to be like 108 degrees or more so even if you have enough pressure to sink the exposed facets into the steel, it will cut very wide shallow furrows (and a more gently scalloped edge) compared to the sharper angles of something like diamond or CBN which would make deeper narrower furrows (and probably a more saw-like edge).

Crystal shape and size are both important. Also the resiliance, bond strength and poroisty of the binder can make a significant difference.... if the binder has a little bit of give, not only can the average height grains sink in a little so the low lying grains can touch the work, the high riding grains can also sink in the average height of the rest of the grains thus increasing the number of grains in actual contact with the work... increases the speed and produces a more even scratch pattern than hard sintered abrasives. Shapton pro stones are resin bonded like this, as are rubber and shellac bonded CBN and diamond wheels (the resin is very dense and stiff on a macro scale though so they can seem quite hard and give very little "road feel").

The amount of grit per unit volume matters too... too much grit will make the stone seem slower as the grains can't sink in and get a good bite in harder steel. Sort of like a bed of nails... the more nails there are, the less they hurt.. Need just enough particle density to grind efficently, but also have to keep it low enough that each grain can get a good bite.

I've read articles on picking the right grindstone for industrial tooling (I was really bored) and it seems to be a bit of a black art balancing the abrasive material, partical size, porosity and bond strength (needs to shed grit at the same rate as the edges of the grains dull) to match the material they are grinding to a particular finish.

We have to suffer the same thing with manual stones, except they only give us grit numbers so we pretty much have to try different stones out on whatever steel we're sharpening.

Originally Posted by yuzuha

Hi, it appears that Olivia took the jis tables from one of my pages...

Certainly not, but your page might be the source for the guy who gave it to me.

Originally Posted by yuzuha

One really interesting thing to note on the detailed table though is the maximum size. 8000 grit can have a few percent 6 micron particles, which can put some dandy scratches in mean 1.2 micron finish. Also the 3% tails are interesting... The 3% below .6 microns is not very important but again it allows 3% to be between 3.5 and 6 microns and still be listed as 8000 grit!

Pam,

Welcome to the SRP!

That's some good stuff there, and you put it in a very understandable language.

You may have answered a question or two that is somewhere around here - The random scratches in the edge of the razor that Olivia was posting about could be caused by this percentage of fluctuation.

Originally Posted by yuzuha

Hi, it appears that Olivia took the jis tables from one of my pages... I can't give you a reference for the data to proove its accuracy, but I spent about a year with a kanji dictionary and yahoo.co.jp searching before I found a Japanese industrial abrasives manufacturer that had a detailed JIS chart showing both the old and new JIS down to this level of detail in a gif image that copied into text format:
http://members.cox.net/yuzuha/jisgrits.html
(I did not list the old JIS standards to that detail since the sedimentation tube method is obsolete but I did list a partial comparison of the old and new JIS on my Shapton grit page http://members.cox.net/yuzuha/jisgrit1.html The yellow numbers on here are purely theoretical and I calculated them for comparing Shapton's grading system to other stones and micron graded powders etc. )

Alas, I can no longer point you to the original site where I found the JIS information because the PC I had all that on died several years ago.... I also no longer have the complete details of the old JIS standard (you can download the standards from the JIS organization in English or Japanese but they charge a considerable fee to do so).

One really interesting thing to note on the detailed table though is the maximum size. 8000 grit can have a few percent 6 micron particles, which can put some dandy scratches in mean 1.2 micron finish. Also the 3% tails are interesting... The 3% below .6 microns is not very important but again it allows 3% to be between 3.5 and 6 microns and still be listed as 8000 grit!

BTW, I discovered that some of you also hang out on knife forums but some of you may not.... you can still find some useful stuff in the useful links sub forum of the kitchen knife forum over there... http://www.knifeforums.com/forums/showtopic.php?tid/759892/
http://www.knifeforums.com/forums/showtopic.php?tid/759541/
for example.

Lots of sources for stones anyway Might find some razor discussion in the "kitchen" and "keeping sharp" forums too.

The JIS information in this list did originally come from your page first!

I have since referenced most of the information from http://www.metallographiebedarf.de/d...oesse_fepa.pdf
and from another manufacturer, though a firefox crash before I thought to book mark it has kept it out of the references...

But, they both corroborate your figures nicely.

Originally Posted by yuzuha

Hi, it appears that Olivia took the jis tables from one of my pages... I can't give you a reference for the data to proove its accuracy, but I spent about a year with a kanji dictionary and yahoo.co.jp searching before I found a Japanese industrial abrasives manufacturer that had a detailed JIS chart showing both the old and new JIS down to this level of detail in a gif image that copied into text format:
http://members.cox.net/yuzuha/jisgrits.html
(I did not list the old JIS standards to that detail since the sedimentation tube method is obsolete but I did list a partial comparison of the old and new JIS on my Shapton grit page http://members.cox.net/yuzuha/jisgrit1.html The yellow numbers on here are purely theoretical and I calculated them for comparing Shapton's grading system to other stones and micron graded powders etc. )

Alas, I can no longer point you to the original site where I found the JIS information because the PC I had all that on died several years ago.... I also no longer have the complete details of the old JIS standard (you can download the standards from the JIS organization in English or Japanese but they charge a considerable fee to do so).

One really interesting thing to note on the detailed table though is the maximum size. 8000 grit can have a few percent 6 micron particles, which can put some dandy scratches in mean 1.2 micron finish. Also the 3% tails are interesting... The 3% below .6 microns is not very important but again it allows 3% to be between 3.5 and 6 microns and still be listed as 8000 grit!

BTW, I discovered that some of you also hang out on knife forums but some of you may not.... you can still find some useful stuff in the useful links sub forum of the kitchen knife forum over there... http://www.knifeforums.com/forums/showtopic.php?tid/759892/
http://www.knifeforums.com/forums/showtopic.php?tid/759541/
for example.

Lots of sources for stones anyway Might find some razor discussion in the "kitchen" and "keeping sharp" forums too.

After spending more time digesting this (JIS grit table for Japanese water stones in microns (electrical resistance method)) chart you posted.....

That is quite some variance! With variance numbers like that concerning the 97% rule and the 3% possible maximum.....That kinda sucks!

but, like jendeindustries said, you have answered some questions... Thank You!